NITES EnMS – Technical Solution for Energy Efficiency

In the previous conversations with Miodrag Skrbic, founder and president of NITES Group, and Vanja Ozegovic, CTO of NITES Group, the principles and NITES experiences were presented, and then also the conceptual design of EnMS (Energy Management System). In this article, Vanja Ozegovic, CTO of NITES Group, presents the technical solution of NITES EnMS.

The implementation of the ISO 50001 standards requires the organization to manage the data on the consumption of energy in real time. It is only that way that the organization is capable of properly assessing its installation, overseeing its progress and realizing the cycle of a constant improvement that the ISO 50001 standard requires. In order to achieve this goal, it is necessary to select and implement a suitable solution which uses certain technologies for energy efficiency.

The characteristics and architecture of the system

The basic characteristics of the NITES EnMS solution are:

1. STRAIGHTFORWARD INSTALLATION: The possibility of relying on meters which can be simply configured and integrated into the online platform, which helps establish the analysis of energy consumption more quickly.

2. SCALABLE FUNCTIONALITY: It entails the choice of a technology which covers the current basic needs of the organization, but at the same time offers more advanced tools for the upcoming period. That way, the organization can fulfill the obligation of a continuous progress promoted by the ISO 50001 standard.

3. EASY TO USE AND HIGHLY VISUAL: Without an additional effort in learning how to use new technological platforms. The organization needs to make sure that the technology that is implemented is easy to learn and proactive relative to the end-user.

4. POSSIBILITIES FOR COLLABORATION: The ISO 50001 promotes the implications of the entire organization, especially the management, into the energy plan. The technology is supposed to help achieve this goal, for example, by offering the possibility of creating control boards for each role in the organization.

5. ISO 50001 CUSTOMIZABLE REPORTS: The technical system should be able to create personalized reports which are 100% adaptable to the operations of the organization and to the ISO 50001 standard. These reports help the organization in the process of preparing the documentation, and primarily in the subsequent reviews, when it is necessary to renew the certificates.

The architecture of the NITES solution supports EnMS as a fully open system. In practice, this means that all the technical and communications devices are not limited to the support of only one producer/supplier in the market. All the devices have their functional parameters, which are defined and can be configured based on publicly available technical standards or other regulations.

NITES recommends to its users for the archiving of the data to be centralized in two phases, so as to minimize their potential loss. In the short term (by the order in the course of a day), on the level of the facility which the system supervises, and, in the long term, at a suitable central place which has adequate computer resources, application solutions and necessary data for a subsequent analysis, estimate and display of data (“control center”).

The transfer of data from individual facilities to the control center must meet the requirements of adequate protection of data through the use of the existing communications structure of the organization to the end of reducing the costs.

NITES EnMS does not exist as a single-purpose system, that is, it is not focused only on collecting, validating and estimating the data of smart meters (AMI – Automated Metering Infrastructure), but is a basic block for the future BMS (Building Management System). By the implementation of suitable regulatory elements, BMSs enable remote control and the operations of the building equipment (source of heat, source of cold, lighting, HVAC etc.). In addition to that, BMSs can be used for supervision, protection from theft or disaster and for providing other additional functionalities.

Data collection and transfer

The number of the variables that are monitored and the manner in which the data are collected are adapted to local conditions.

In order to transfer the measured data from the meters and sensors to the control center, it is necessary to primarily set the requests for the lowest error rate, or, more accurately, the loss of data. If the data in the meters are not archived, the potential error in their transfer, for example, due to clashing with another communications device, will lead to their irretrievable loss. The transfer of data therefore needs to be protected from mistakes. There are several possible approaches, and they depend on the selected communications protocol, the topology of the collection of data and the meters and sensors that are used.

In the cases when the meters and sensors in the organization are already installed, NITES EnMS adapts to certain specificities of the organization’s locations. Several communications channels are used, including: Ethernet, optic fibers, Wi-Fi, BPL, PLC, RS232/485, GPRS, RF network, ZigBee, M-Bus, MODBUS etc.

Multiple protocols are supported, including: DLMS / Cosem, IEC1107, IEC61107, IEC 62056-21, LonWorks, Euridis, M-Bus, impulses. Several different suppliers of smart meters are supported.

The data from individual meters and sensors are collected in one place and temporarily archived. The collection function is enabled by hardware and software data concentrators, which at the same time convert the received data into a different communications protocol and/or another physical layer which is used for data transfer. One concentrator can be used for a larger number of measuring spots, and their number is determined depending on the positions of the meters in facilities and the targeted performances.

The concentrators can be programmed and they offer several functionalities (for example, the possibility of receiving data from other types of counters which feature an analog or binary data transfer).

At the level of the control center, all EnMS subsystems communicate with each other in the same way all other information systems of the organization do, using the standard ESB (Enterprise Service Bus), based on the IEC 61968 standards.

Monitoring methods

As for the specification of the suitable meters and sensors that would monitor the consumed quantities of energy at a necessary frequency, some options are listed below.

In the case of electrical energy, the collection of data is solved based on the type of the installed meter. For constant metering spots (that, is A-, B-, or possible S-type measuring, which is usually connected to the distribution system with a reserved power of 100 kW and more, or with the main switch of nominal electricity of 200 A and more), the most cost-effective thing to use are 15-minute data values that the local distribution company makes available to purchasers. However, consumption patterns are available with a one-day delay, which makes them unsuitable for consumption management in real time.

The second option, which can also be used for subtraction spots (C-type measuring), is to enable an impulse outlet S0 beneath the casing of the meter and to install an impulse sensor with an integrated communications module next to the meter. This solution has limitations regarding its usefulness in the management of real time sampling.

The third option is the installation of the secondary electronic meter of a suitable type, with the possibility of a continuous measuring of all the main values (electricity and voltage at every phase, active and reactive induction or capacity power in both directions). The meter should have a high-capacity data outlet (preferably Ethernet) and, depending on the concentrators used, can have a memory for the recording of profiles or not (aggregated 15-minute values in one hour).

The cables between the meter and the concentrators are purposefully arranged so as to ensure a reliable transfer of data. The continuous data measuring then enables the future use of the meter for the optimization of the size of the switch or the agreed peak of 15-minute consumption in one hour.

In the case of subtraction spots with a current consumption of 100 A, direct measurements can be installed, and indirect sampling is already standard for outlets with higher power demands (using the measurement transformers/coils set on each phase, which measure the consumption characteristics and transferring them to the meter).

The submeters installed on selected subsamples can then be addressed with more accessible models (whether an electronic type with an Ethernet data outlet or an impulse outlet and data communication equipment).

Archiving of data, analysis and projection

There are several reasons for a central archiving of data. The first and most important one is to enable the organization to have a central register of the amount of energy that is spent in various forms.

The control center serves the needs of a long-term electronic archiving of data, their continuous analysis and subsequent evaluation. In conventional systems for data collection from a large number of meters, NITES AMM (Automated Meter Management) is used. The archiving of data is only one of the functions that NITES AMM provides.

The NITES MDM (Meter Data Management) system works on processing the data collected and archived by AMM, as well as the manually collected data from old electro-mechanical meters.

The existence of a large quantity of historical data on consumption is an invaluable basis for data analysis and energy management. If long enough time series of consumption of energy of individual organizational units are available, it is possible to model the consumption of the organization in the next period, with additional knowledge on the estimated development of climate conditions (Targeting).

If there are several buildings that are used for the same purpose (for example, for educational or social purpose), there is another possibility, where they need to be compared by absolute values, or better yet, by conversion into an adequately selected reference unit, such as the floor area or the number of people that are usually present (Benchmarking).

This way, it is possible to identify the devices that spend the energy the most and pay special attention to them.

Another useful function of the system is that it can check with precision how the subsequently adopted measures of energy saving will reflect in any other set technical or mandatory measures. This way, with NITES EnMS, it is possible to better estimate the advantages of certain set measures for the reduction of the consumption of energy and propose potential improvements for achieving even better results in the future, when the solution is implemented in other facilities and buildings of the organization.

In the case of electrical energy, when implementing continual measuring of consumption, it is possible to compare the measured data with respect to the liminal capacity of consumption with the current state (which needs to be entered into the system initially). For example, the result can be the conclusion that the reason for the main switch being overloaded is that one of the phases is overloaded or that there is simply no awareness of the possibility of its lowering.

The ability of the system to identify inefficiency improves with time as the amount of the data collected at the observed devices grows or as their number increases.

The implemented system acquires a gradual “intelligence” and can become a true central dispatcher for buildings and facilities, especially if it is gradually upgraded with other functions, such as the monitoring of technologies and potential malfunctions, the possibility of an intervention of the handlers, predictive control of the sources of heat or a change in climate conditions.

A system set up that way will certainly not need to be fully redesigned.

After the NITES EnMS solution is selected, the next step entails the preparation of the specification of costs and potential savings, as well as a plan and time deadlines for the implementation, all to the end of a long-term sustainability.

Nites d.o.o. Beograd

NITES Group

Vanja Ožegović

Miodrag Škrbić

NITES EnMS

standard ISO 50001

Ethernet

optic fibers

Wi Fi

BPL

PLC

RS232 485

GPRS

RF network

ZigBee

M Bus

MODBUS

management of data on energy consumption in real time

energy efficiency technology